1. Field of the Invention
The present invention relates to a vehicle seat with a seat padding, in particular for an aircraft seat.
2. The Prior Art
The invention relates to a seat cushion as described in the generic part of claim 1.
A known seat with a padding of foamed plastic--in accordance with WO-A1-87/06894 of the same applicant--consists of a foamed plastic with a supporting body made of an open-cell elastic plastic foam having a first specific gravity and with a flame-retardant layer made of an open-cell elastic foamed plastic, provided with flame retardant, having a second specific gravity different from the first. The plastic foam and the flame-retardant layer are connected with each other, in particular through a foaming process, and are surrounded by an upholstery material which is highly flame-resistant. In order to achieve a sufficient permeability to air of such a padding, it was also proposed, after the completion of the padding, to push needles through this padding, so that a corresponding exchange of air is possible. These paddings have proved, in themselves, to be very good in practice, but it has been found however, that especially in extreme weather conditions or under various climatic conditions the comfort of the seats was not sufficient for the planned purpose of use in vehicles.
In addition, seats for public transport are already known--in accordance with DE-GM 85 06 816--which have a seat padding which is covered with a seat upholstery, in which the seat upholstery and the seat padding consist of a highly flame-resistant and smokeless material. Frequently, one proceeds here such that between that flame-resistant seat upholstery and the seat padding, which mostly consists of plastic foam, a glass fibre mat is arranged, which is intended to prevent the seat upholstery from burning through in the direction of the seat padding. However, it has been found here that in many cases the action of the flames originates from the floor, and the plastic foam of the seat padding tends to burn with the development of thick smoke, whereby the public transport is filled with smoke in a very short period of time, when fire occurs, so that it is scarcely possible for the occupants to find their way. Accordingly, in this known seat, provision is made that beneath the seat padding in the supporting frame of the seat a fire-resistive plate is arranged. Therefore, a particular section must be used to hold the seat padding and also additional production costs are necessary for arranging the fire-resistive plate. Also, the seat ventilation was not satisfactory in this form of embodiment.
Seats with paddings of foamed plastic are very widely used in modem vehicle construction. Above all, they are used in rail and road vehicles, but also, predominantly in aircraft. Whilst the regulations which apply to rail vehicles as regards the self-extinguishing structure of the materials used or as regards the generating of smoke, prescribe very strict guidelines, these regulations are further exceeded by the regulations which apply in the aircraft industry. Thus, in seats which are permitted for use in aircraft, a test is prescribed, in which the paddings are directly exposed to a flame from a burner, in their composition as provided for installation. This flame acts directly on the padding for a period of 2 minutes after which the flame is extinguished or removed. If the flames do not extinguish themselves by then, the padding is extinguished after 5 minutes. After this fire test, the weight loss of the padding must not be higher than 10%. In order to fulfill these extremely strict regulations, and at the same time to achieve a high degree of comfort in the seats in the case of long-haul flights, and to achieve a low weight, seat paddings of various elastic, open-cell soft foam materials, provided with flame retardants, and having differing specific gravities, were glued together.
Such a known vehicle seat--according to EP-A1 190 064--consists of several layers of needle batt, which are surrounded by a non-flammable upholstery material. Between the upholstery material and the individual layers of needle batt, reinforcement mats of metal or respectively glass fibres are arranged, in order to reduce damage by vandals. Through the glueing of the individual layers and the many intermediate layers, it is even more difficult to achieve a sufficient ventilation in the known vehicle seat.
In another known seat for aircraft, in order to create the complex spatial profiling of the seat paddings more simply, the supporting body is formed from a piece which is treated with flame retardants and is foamed in one piece in a mould, the surface of which piece is covered with a flame-retardant layer and thereafter with a non-flammable upholstery material. In the known seats, however, the new, increased safety specifications and testing regulations for aircraft seats could not be fulfilled.